By Scott Levine
The last few weeks have been difficult and scary, and it might be hard to escape all the dread.
Like others through history, I’ve long found that one of the best ways to catch my breath is taking a few minutes outside under the stars. There’s a surprising comfort and togetherness that comes with looking out into the galaxy and letting your eye and mind go where it wants.
A fun exercise is thinking not just about the stars, but also where they are in space. The stars in most of the groups we see each night are unrelated and only appear grouped together because of how we perceive our point of view on them. Who knows what we’d see from some other corner of the galaxy?
If you’ve lingered a little and looked closely at the sky near Venus, which we talked about last month, you may have noticed two small groups of stars just a short way above it. These groups, unlike most others, are two of the nearest open clusters to us. Their stars are gravitationally tied to each other and travel the galaxy together.
The V-shaped Hyades cluster, above and toward the left of Venus, is about 150 light years away. A light year is the distance that light, the fastest thing in the universe, travels in a year. That’s about six trillion miles. So, the Hyades you see tonight is actually the Hyades of the 1870s.
The bright red star at the top of the V is Aldebaran, a red giant about 65 light years away. That means Aldebaran isn’t in the cluster; it’s in front of it, about halfway between us and Hyades. Maybe you can imagine this in three dimensions, like you’d see a tree in your yard in front of those across the street.
Still farther, about 450 light years, is the tiny dipper-shaped Pleiades cluster, also known as the Seven Sisters. This is a group of hot, blue stars surrounded by glowing dust. You can probably see five or six with the naked eye, but through binoculars you can see countless brilliant diamonds spilled across the black velvet of the deep sky.
This all brings us back to Venus. As you head out Tuesday night, you’ll see Venus in a wonderful conjunction with the Pleiades cluster. Keep checking in this week, and watch as the planet and the cluster appear to creep toward each other. They’re close on the night of Mar. 31 but will be even closer on Apr. 1. On the nights of Apr. 2-4, Venus meets and travels through the cluster. Remember this is an illusion. They’re still extremely far apart. Venus is actually crossing in front the cluster from our point of view.
I’m curious how this will look. Venus is about 600 times brighter than the deep and dusty stars in the cluster. Will it overwhelm them? Will it look like the boldest and brightest of the rest of the gems? Stay tuned, and drop me a note if you can see it. I’d love to hear what you think.
A trip out under the stars might not be able to fix anything, but they can help you forget for a few minutes. I hope you can find a little time to have a look and reach out to some old friends in the galaxy. Please stay safe and healthy, and let’s catch up here next month.
Scott Levine (firstname.lastname@example.org) is an astronomy writer and speaker from Croton-on-Hudson. He is also a member of the Westchester Amateur Astronomers, who are dedicated to astronomy outreach in our area. For information about the club including membership, newsletters, upcoming meetings and lectures at Pace University and star parties at Ward Pound Ridge Reservation, visit westchesterastronomers.org. Events are free and open to the public.
Please Note: All in-person club activities are suspended until further notice due to concerns over COVID-19.